I installed the NV Silencer 5 on my GeForce 6800gt about six months ago. It works great and I think it's in the same noise ballpark as the older VGA Silencer on "low". Not quite, but close. Great product, directly pipes the GPU heat out of the case the way it should be. Couldn't be happier.
However, within the last month the fan developed an annoying rattling sound. It varied in noise, from across-the-room LOUD to merely noisy. Oddly enough, smacking the top of the tower case (I have the Lian-Li V2000, so the mounting is upside down-- the VGA card is very close to the top of the case and facing up) .. made the rattling go away. But when I'd wake the computer up the next day, sometimes the rattling would be back. A quick Fonz-style smack, and it'd be quiet again. Until I woke it up or restarted it.
Anyway, I eventually got sick of the Fonz aaaaaaaaaaaayyyyy! routine. I opened the case, removed the card, detached the NV Silencer 5, and examined the fan. I've talked about lubricating fans before (and there's another thread here), and luckily the design of the Silencer leaves the fan lubrication port exposed (eg you don't have to disassemble the whole thing):
Remove that black "AC" sticker, then the shiny silver one underneath, and the fan lubrication port is exposed.* I topped the port off with a generous amount of teflon based Tri-Flow, then used compressed air to spin the fan at, uh, great speeds. That should let it work its way in. I cleaned up with a paper towel, then repeated this exercise. I wanted that thing super-lubed. I left some of the tri-flow in place and taped over the lubrication port a few times to keep it in there. I then left it sitting in the correct "gravity down" orientation so the lubrication could seep in.
Anyway, after this, I re-installed and I'm happy to report that the rattling fan noises are gone.
* Does dirty computer talk make you randy? Behave!
